Suspension and traction media interface for elevators

ABSTRACT

A system for coupling a suspension medium to a load carrying structure of an elevator installation includes a frame and a hitch plate. The frame has two spaced apart side walls, wherein the side walls are positionable to receive a part of the load carrying structure between the side walls. Each side wall has a receptacle having a longitudinal shape. The hitch plate has at least one fixture configured to couple to a sheave arrangement for the suspension medium. Each receptacle is sized to movably receive a section of the hitch plate so that the hitch plate extends between the side walls and is rotatable about a vertical axis.

BACKGROUND OF THE INVENTION

The various embodiments described herein generally relate to elevatorinstallations. More particularly, the various embodiments describedherein relate to a system and method for coupling a suspension medium toa load carrying structure of an elevator installation.

In one example of a known elevator installation, a suspensionmedium—such as a rope or flat belt-type rope—interconnects acounterweight and a cabin. A drive motor causes the suspension medium tomove in order to thereby move the counterweight and the cabin up anddown along a hoistway. The suspension medium loops around at least onesheave system, which may be mounted to the cabin or the counterweight,or both. The sheave system is, for example, mounted a frame of thecabin.

U.S. Pat. No. 7,665,580 discloses several sheave systems arranged nextto each other on the counterweight or the cabin. Each sheave system hasa U-shaped carrier in which a deflecting roller and a ball socket arepositioned. The deflecting roller is mounted between the legs of theU-shaped carrier, and the ball socket exists in a curve that connectsthe two legs. A flat belt-type suspension medium loops around thedeflecting roller. A tie bolt is part of the ball socket and extendsfrom the carrier towards a support structure of the counterweight orcabin. The tie bolt is fixed in a through hole of the support structure.Further, each sheave system is individually rotatable and adjustableabout an axis parallel to a take-off direction of a respectivesuspension medium.

Even though such sheave systems have a variety of advantages, forexample, because they are individually rotatable, these sheave systemsmay not be suitable for certain applications. For example, if anelevator installation is subject to modernization and the existing cabinframe and counterweight are to be retained without any modification, itmay not be possible to provide the frame with, for example, the requiredthrough holes for the tie bolts, or to adjust the sheave system forvarying hoistway layouts. There is, therefore, a need for an alternativetechnology for coupling a suspension medium to a cabin or counterweightthat overcomes these limitations.

SUMMARY OF THE INVENTION

Accordingly, on aspect of such an alternative technology involves asystem for coupling a suspension medium to a load carrying structure ofan elevator installation. The system includes a frame and a hitch plate.The frame has two spaced apart side walls, wherein the side walls arepositionable to receive a part of a yoke of the load carrying structurebetween the side walls. Each side wall has a receptacle having alongitudinal shape. The hitch plate has a least one fixture configuredto couple to a pulley device for the suspension medium. Each receptacleis sized to movably receive a section of the hitch plate so that thehitch plate extends between the side walls and is rotatable about avertical axis.

Another aspect involves an elevator installation having a suspensionmedium, a sheave arrangement, coupled to the suspension medium, a loadcarrying structure, and a coupling system configured to couple thesheave arrangement to the load carrying structure. The coupling systemincludes a frame and a hitch plate. The frame has two spaced apart sidewalls, wherein the side wails are positionable to receive a part of ayoke of the load carrying structure between the side walls. Each sidewall has a receptacle having a longitudinal shape. The hitch plate has aleast one fixture configured to couple to a pulley device for thesuspension medium. Each receptacle is sized to movably receive a sectionof the hitch plate so that the hitch plate extends between the sidewalls and is rotatable about a vertical axis.

Yet another aspect involves a method of coupling a suspension medium toa load carrying structure of an elevator system. A hitch plate ispositioned above a part of the load carrying structure, and sidewallsare mounted to the hitch plate so that sections of the hitch plate arerotatably positioned in receptacles of the sidewalls and the part of theload carrying structure extends between the sidewalls. The sidewalls areopposite each other and extend in parallel planes. Further, a sheavearrangement is mounted to the hitch plate, wherein the sheavearrangement is configured to receive the suspension medium.

In one embodiment, the plate has a circular shape. The circular shapeallows the hitch plate to be adjusted to a desired angle in a rangebetween about 0° and about 360°. This provides for a high flexibilityand usability of the system.

Sections of the circularly shaped hitch plate extend through thereceptacles of the hitch plate. Such a mounting of the side walls to thehitch plate provides for a secure engagement between these componentsthat can be easily verified and inspected by an installer.

The at least one fixture of the hitch plate includes an opening sized toreceive a rod of the pulley arrangement. Advantageously, this allows thepulley arrangement to be mounted “from above”, i.e., in verticaldirection, while the coupling system is already mounted to the loadsupporting structure, which also facilitates the installation procedure.In one exemplary embodiment described herein, a plurality of theopenings is positioned along a straight line. That linear arrangement ofthe openings corresponds to the arrangement of the suspension media inthe elevator shaft facilitating their alignment with the couplingsystem.

In one embodiment, a predetermined number of longitudinal elementsextends between the side walls and interconnects the side walls. Eachside wall has a corresponding number of passageways, each removablyreceiving an end section of the longitudinal element. This assists inassembling the coupling system “element-by-element” around the loadcarrying structure.

Furthermore, each side wall has an upper part containing the receptacle,and a bottom part having an opening for a crossbeam. The crossbeam, or agroup of crossbeams, are thereby secured to the coupling system andcarry the load carrying structure.

In one embodiment, first setscrews extends through the hitch plate andare configured to press against an upper surface of the supportstructure for vertical positioning of the coupling system with respectto the load carrying structure. Second setscrews extend through the sidewalls to press against sides of the load carrying structure forhorizontal positioning of the coupling system. These two sets ofsetscrews allow the separate alignment of the coupling system withrespect to the load carrying structure, which also assists infacilitating the installation procedure.

Each setscrew may have a bearing surface pressing against the loadcarrying structure that includes a material that dampens vibrations.Advantageously, the bearing surface prevents (or at least dampens)vibrations from propagating into the load carrying structure and thecabin.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The novel features and method steps characteristic of the invention areset out in the claims below. The invention itself, however, as well asother features and advantages thereof, are best understood by referenceto the detailed description, which follows, when read in conjunctionwith the accompanying drawings, wherein:

FIG. 1 shows a schematic illustration of one embodiment of an elevatorinstallation with a sheave arrangement and a system for coupling asuspension medium to a load carrying structure;

FIG. 2 is a schematic illustration of one embodiment of the sheavearrangement and the system for coupling the suspension medium to theload carrying structure shown in FIG. 1;

FIG. 3 is a schematic illustration of one embodiment of the system forcoupling the suspension medium to the load carrying structure shown inFIG. 2;

FIGS. 4 and 5 are schematic side views of the system for coupling thesuspension medium to load carrying structure of FIG. 3;

FIG. 6 is a schematic top view of the system for coupling the suspensionmedium to load carrying structure of FIG. 3;

FIG. 7 is a schematic bottom view of the system for coupling thesuspension medium to load carrying structure of FIG. 3;

FIG. 8 is a flowchart of one embodiment of procedure for installing thesystem for coupling the suspension medium to load carrying structure;

FIG. 9 schematically illustrates an arrangement of a sheave arrangementset up perpendicular to a line that connects a cabin centerline with acounterweight centerline; and

FIG. 10 schematically illustrates the arrangement of FIG. 9 skewed frombeing perpendicular.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically illustrates one embodiment of an elevatorinstallation 1 installed in a multi-story building. The elevatorinstallation 1 includes a cabin 2 connected by a suspension medium 4with a counterweight 6, wherein the cabin 2 and the counterweight 6 aremovable up and down in opposite directions in a vertically extendingshaft 8. A drive 10 is provided below a shaft roof and next to astructure 20. Depending on whether the elevator installation 1 isprovided with or without a machine room, the structure 20 may be a floorof a separate machine room, which houses the drive 10, or a supportstructure provided below the shaft roof; a space below the shaft roof issometimes referred to as an overhead space. In the latter situation, thestructure 20 is mounted to a shaft wall to support the drive 10 inproximity of the shaft wall.

The drive 10 is configured to drive the suspension medium 4 to move thecabin 2 and the counterweight 6. In one embodiment, the elevatorinstallation 1 is a traction-type elevator, i.e., a drive sheave coupledto the drive 10 acts upon the suspension medium 4 by means of tractionbetween the drive sheave and the suspension medium 4. In such anembodiment, the suspension medium 4 serves as a suspension and tractionmedium.

The elevator installation 1 includes further a load carrying structure14 that carries the cabin 2. The load carrying structure 14—alsoreferred to as “sling”—includes a yoke, crosshead, or frame that atleast partially surrounds the cabin 2. The cabin 2, empty or loaded withgoods or passengers, constitutes a load to be carried by the loadcarrying structure 14. It is contemplated that the cabin 2 includes atleast one door on one side of the cabin 2; however, for ease ofillustration, FIG. 1 does not show a door or any other component of thecabin 2.

A system 12 for coupling the suspension medium 4 to the load carryingstructure 14 interfaces the load carrying structure 14 and thesuspension medium 4. This system is hereinafter also referred to ascoupling system 12. It is contemplated that the coupling system 12 maybe provided at the counterweight 6 to interface the counterweight 6, ora frame of the counterweight 6, and the suspension medium 4. Theelevator installation 1, therefore, may have the coupling system 12 atthe load carrying structure 14 or the counterweight 6, or both.

In the illustrated elevator installation 1 of FIG. 1, terminal ends ofthe suspension medium 4 are fixed at fix points 16, 18 to the structure20. Starting at the fix point 16, the suspension medium 4 extendsdownwards, loops around a sheave arrangement 22 of the system 12 andextends upwards towards the drive 10. There, the suspension medium 4loops around a drive sheave 24 of the drive 10 and extends towards adeflection roller 26 positioned next to the drive 10 above the structure20. The deflection roller 26 guides the suspension medium 4 sideways sothat the up and down movement of the counterweight 6 does not interferewith the up and down movement of the cabin 2. At the deflection roller26, the suspension medium 4 extends downwards, loops around a sheave 28at the counterweight 6 and extends upwards towards the fix point 18.This configuration of the suspension medium 4 is typically called a 2:1configuration. It is contemplated that in other embodiments of theelevator installation 1 other configurations, e.g., 1:1 or 4:1, may beused; the number of sheaves, rollers and fix points may then varydepending on a particular embodiment.

Independent of any particular roping configuration or structure of theelevator installation 1, the suspension medium 4 may have one of severalconfigurations. In one embodiment, the suspension medium 4 has abelt-type configuration in which several cords of metallic material arefully or partially embedded in an elastomeric coating. Thatconfiguration has a cross-section having a width that is longer than itsheight. The surface of such a suspension medium 4 may be flat or havelongitudinal grooves. In another embodiment of a suspension medium 4with such a cross-section, cords of non-metallic material, such asaramid fibers, are fully or partially embedded in an elastomericmaterial. In yet another embodiment, the suspension medium 4 may have around configuration in which individual cords of metallic ornon-metallic material are twisted to a rope. Such a round suspensionmedium may be uncoated or coated with an elastomeric material.

It is contemplated that the elevator installation 1 may in certainembodiments include more than one suspension medium 4. The number ofsuspension media 4 used in the elevator installation 1 depends, forexample, on the load capacity of the cabin 2. In the embodimentsdescribed with respect to FIG. 4-7, the elevator installation 1 includesfive suspension media 4, each having a belt-type configuration, asdefined above. The number of suspension media 4 affects the number ofsheaves and rollers used in the elevator installation 1. Each sheave androller acts typically on only one suspension medium 4.

FIG. 2 is a schematic illustration of one embodiment of the sheavearrangement 22 and the coupling system 12 shown in FIG. 1. As the numberof suspension media 4 is five, the sheave arrangement 22 includes fiveindividual sheaves 22 a. These individual sheaves 22 a are arranged inparallel, and may be positioned at an angle that is not perpendicular tothe linear arrangement of a hole pattern in a hitch plate 32 (describedbelow with reference to FIGS. 3 and 6). Each individual sheave 22 aincludes a U-shaped housing with a sheave roller 22 b mounted betweenthe legs of the U-shaped housing. The suspension medium 4 loops aroundthe sheave roller 22 b. A tie bolt 22 c is part of the ball socket andextends from the housing towards the coupling system 12. The sheavearrangement 22 is in one embodiment similar to the sheave systemdisclosed in U.S. Pat. No. 7,665,580 and described above.

Referring to FIG. 2 and FIG. 3, which shows the coupling system 12 ofFIG. 2 without the sheave arrangement 22, the coupling system 12includes a frame that has two spaced apart side walls 30, which extendin parallel planes. The side walls 30 are positionable to receive a partof a yoke of the load carrying structure 14 (in FIG. 2 indicated bydashed lines) between the side walls 30. The side walls 30 aresubstantially parallel to each other. Each side wall 30 has a receptacle38. In the illustrated embodiment, each receptacle 38 has a longitudinalshape. Rods 34 interconnect the side walls 30 and, hence, allowpositioning the yoke between the side walls 30. The rods 34 extend in adirection that is substantially perpendicular to the parallel planes ofthe side walls 30, and allow the side walls 30 to adjust to be securelyfixed around a width of the load carrying structure 14.

As shown, e.g. in FIG. 2, each side wall 30 has a generally rectangularshape, wherein through holes for the rods 34 are located in corners ofthe rectangular shape. In the illustrated embodiment, the couplingsystem 12 includes four rods 34, each having a circular cross section.However, it is contemplated that more or less rods 34 may be used, orthat the rods 34 may have a different profile, e.g. a non-circular crosssection, as long as the rods 34 allow the secure positioning of the yokebetween the side walls 30.

The coupling system 12 includes a hitch plate 32 that extends betweenthe side walls 30 in a direction that is substantially perpendicular tothe planes of the side walls 30. Each receptacle 38 of the side walls 30is sized to movably receive a section of the hitch plate 32 so that thehitch plate 32 extends between the side walls 30 and is rotatable abouta vertical axis. The receptacle 38 allows the hitch plate 32 to berotated 360° into any position necessary for a correct alignment of thesuspension medium 4. The receptacle 38 and may have another shape aslong as it secures the hitch plate 32 and allows rotation of the hitchplate 32. The hitch plate 32 has a least one fixture configured tocouple to the pulley arrangement 22. The fixture includes in oneembodiment a through hole for the tie bolt 22 c. In the illustratedembodiment, the hitch plate 32 has five through holes to receive thefive tie bolts 22 c. It is contemplated that not all through holes ofthe hitch plate 32 must be used; in the illustrated embodiment up tofive tie bolts 22 c may be used, others may use less than five.

In the various embodiments described herein, the hitch plate 32 and thereceptacles 38 are located in proximity of an end of each side wall 30.This end of each side wall 30 is hereinafter referred to as upper end,whereas an opposing end of each side wall 30 is referred to as bottomend. The reference to upper and bottom ends corresponds to theorientation of the coupling system 12 within the shaft 8, and the up anddown movements of the cabin 2.

In proximity of the bottom ends, each side wall 30 has at least oneopening 46 configured to receive a crossbeam 36. The crossbeam 36extends through the openings 46 of each side wall 30 substantiallyparallel to the hitch plate 32 and in a direction perpendicular to theside walls 30. The crossbeam 36 is secured at the openings 46, e.g., bymeans of nuts and bolts, or any other means, against unintendedmovement. In the illustrated embodiment, the coupling system 12 includesfour crossbeams 36. However, it is contemplated that the number ofcrossbeams 36 may vary, e.g., due to varying load requirements of aparticular elevator installation 1.

The arrangement of the side walls 30, rods 34, hitch plate 32 andcrossbeams 36 results in a frame structure having an opening with asubstantially rectangular cross section. This opening of the couplingsystem 12 is sized to receive the yoke of the support structure 14. Asshown in FIG. 2 and FIG. 3, the hitch plate 32 is located above theyoke, and the crossbeams 36 are located below the yoke. In use, the yokeand the crossbeams 36 press against each other, e.g., the crossbeams 36carry the load supporting structure.

To secure and/or to adjust the position of the yoke within the opening,the coupling system 12 includes set screws 40, 40 a, 48, 48 a that pressagainst the yoke, as shown in FIG. 4. Each side wall 30 has an opening42 through which a set screw 40 (40 a) extends, as illustrated in, e.g.,FIG. 2 were only one opening 42 is visible. In the illustratedembodiment, the opening 42 is a vertical slot to allow verticalalignment of the set screw 40 with respect to the yoke. The set screws40, 40 a press against side walls of the yoke, and allow the couplingsystem 12 to be adjusted with respect to the yoke of the load carryingstructure 14. The set screws 48, 48 a extend, e.g. via through holes,through the hitch plate 32, and press against upper surfaces of theyoke. Angle elements 50 are mounted to the side walls 30 and have agenerally L-shaped form. The short legs of the angle elements 50 aremounted to the side walls 30, and the long legs each have a longitudinalslot sized to receive the set screws 48, 48 a. The long legs aresubstantially parallel to an upper surface of the hitch plate 32. Theset screws 48, 48 a are movable within the longitudinal slots to allowhorizontal positioning of the hitch plate 32.

FIGS. 4-7 are schematic plan views (cross-section, side view, top view,bottom view) of the coupling system 12 of FIG. 3. The cross-section ofFIG. 4 shows the rectangular opening of the coupling system 12 and thepositioning of the yoke within that opening. The hitch plate 32 extendson both sides through the side walls 30. The set screws 40, 40 a extendthrough the side walls 30, and the set screws 48, 48 a extend throughthe hitch plate 32, all of which press against the yoke. The purpose ofthe setscrews 40, 40 a, 48, 48 a is to fix the position of the couplingsystem 12 in relation to the yoke of the support structure 14 so that,e.g., in case the suspension media 4 ever becomes slack (such as in abuffer strike or safety set), the coupling system 12 will not move fromits initial installed position along the yoke of the support structure14. Each set screw 40, 40 a, 48, 48 a has a cup shaped bearing surfacethat interacts with the yoke. The bearing surface may be of a material(e.g., a plastic material, or a rubber material) that is hard enough toprovide for the fixing of the position of the coupling system 12, but isalso sufficiently soft to dampen vibrations; advantageously vibrationsfrom the suspension media 4 do not, or at least at a reduced magnitude,propagate into the yoke and, therefore, not into the cabin 2. Theremaining part of each set screw 40, 40 a, 48, 48 a is made of metal.

In proximity of the bearing surface, each set screw 40, 40 a, 48, 48 ahas a pair of (counter) nuts to allow adjusting and fixing the length ofthe set screw 40, 40 a, 48, 48 a extending from the underside of thehitch plate 32. The tie bolts 22 c extend through the hitch plate 32,wherein each tie bolt 22 c has in proximity of the bearing surface apair of nuts to allow adjusting and fixing the tie bolt 22 c. In theillustrated embodiment, an optional washer plate 56 may be positionedbetween the underside of the hitch plate 32 and the nuts. It iscontemplated that instead on using such a single longitudinal washerplate, individual washers may be used.

The side view of FIG. 5 shows the arrangement of the crossbars 36 withinthe opening 46 of the side wall 30. In the illustrated embodiment, thecrossbars 36 are equally spaced. In other embodiments, however, thespacing may be different. The illustrated embodiment of the side wall 30has additional openings or cutouts 44 to minimize the weight of the sidewall 30. However, it is contemplated that in other embodiments the sidewall 30 does not have such openings or cutouts 44.

The top view of FIG. 6 illustrates that the hitch plate 32 has a presetpattern of through holes. The tie bolts 22 c are arranged in a line thatextends at an angle with respect to the side walls 30. The angle may beadjusted between about 0° and about 360° depending on a particularembodiment. In addition to the through holes for the tie bolts 22 c, thehitch plate 32 has additional through holes 52 which are arranged in aline that extends perpendicular to the line along which the tie bolts 22c are arranged. The difference between the line of through holes 52 andthe line of through holes in which tie bolts 22 c are arranged, is thatthe line of through holes 52 has an even number of equally spaced holesfor use when the number of suspension media is 2 or 4, and the line ofthrough holes in which tie bolts 22 c are arranged have an odd number ofequally spaced holes for use when one, three, or five suspension media 4are used. In the embodiment of FIG. 3, this hitch plate 32 may be usedwhen the number of suspension media 4 is five or less. That is, a singlehitch plate 32 can be used for up to five suspension media 4. It is alsocontemplated that if more than five suspension media 4 are necessary, asimilar but larger hitch plate with more through holes can be used. Afurther line of through holes 52 may be provided as well. This furtherline of through holes 52 may be provided at any desired angle. The hitchplate 32 may have other through holes 54 which are arranged along theborder of the hitch plate 32 and configured to align with the angleelements 50. These additional through holes 52, 54 provide foradditional flexibility when positioning the hitch plate 32.

The hitch plate 32 has a circular shape of a predetermined diameter andthickness. In one embodiment, its diameter is about 500 mm and itsthickness is between about 50 mm and about 60 mm, e.g., about 50.8 mm.For such a hitch plate 32, the side walls 30 are spaced at a distancebetween about 100 mm and about 350 mm and have a height between about450 mm and about 580 mm, e.g., about 453 mm and about 574 mm. The hitchplate 32 is made of steel, e.g., low carbon steel, or any other materialthat has a sufficient mechanical strength to support the forcesoccurring during typical load conditions plus a predetermined safetyfactor. It is contemplated, that the hitch plate material, diameter andthickness and number of through holes may be selected according to loadrequirements. The same applies to the spacing of the side walls 30 andtheir heights. Advantageously, hitch plate 32 allows for rotation ofabout 360°. Other shapes may have a reduced range of rotation.

The bottom view of FIG. 7 shows again the arrangement of the crossbeams36 and the washer plate 56 mentioned with reference to FIG. 4. A pair of(bottom) rods 34 extends underneath the crossbeams 36, as shown in FIG.7, and a pair of (upper) rods 34 extends above the hitch plate 32, asshown in FIG. 6. Once adjusted, the rods 34 are secured to the sidewalls 30, e.g., by means of nuts screwed onto threaded end sections ofthe rods 34, or any other fastening means.

Having described various embodiments of the coupling system 12 and thesheave arrangement 22, the following describes a method of coupling asuspension medium 4 to the load carrying structure 14. Briefly, thehitch plate 32 is positioned above a part of the load carrying structure14, and the side walls 30 are mounted to the hitch plate 32 so thatsections of the hitch plate 32 are rotatably positioned in receptacles38 of the side walls 30 and the part of the load carrying structure 14extends between the side walls 30. The side walls are opposite eachother and extend in parallel planes. Further, the sheave arrangement 22is mounted to the hitch plate 32, wherein the sheave arrangement 22 isconfigured to receive the suspension medium 4.

Referring to a more detailed description, FIG. 8 is a flowchart of oneembodiment of a procedure for installing the coupling system 12 and thesheave arrangement 22. The procedure may be performed duringmodernization of an elevator installation, e.g., by an installer workingon the roof of the cabin 2. The cabin 2 has been secured by anchoringthe support structure 14 at the guide rails, and, in case of amodernization project, any existing suspension medium, e.g., has beenremoved.

In a step S1, the hitch plate 32 is positioned above the yoke (orcrosshead). The hitch plate 32 may be hoisted and/or anchored above theyoke, e.g., centered along the length of the yoke.

In a step S2, the required hole pattern is selected and an interfaceangle is determined. The interface angle is the angle at which the hitchplate 32 is to be placed for a correct alignment of the suspensionmedium 4, i.e., to offset any twist in the suspension medium 4 betweenthe cabin 2 and the counterweight 6. In one embodiment, the hole patternshown in FIG. 6, i.e., five suspension media 4 in a row, is selected.

The interface angle is dependent on the location of the counterweight 6in the hoistway, and the position of the drive 10 (bedplate), e.g., inthe machine room. Typically, the linear sheave arrangement 22 is set upperpendicular to a line that connects a centerline of the cabin 2 with acenterline of the counterweight 6, as shown in the top view illustrationof FIG. 9. However, for some installations, this is not possible, andthe linear arrangement is skewed from being perpendicular, as shown inthe top view illustration of FIG. 10. In these cases, each sheave 22 ain the particular sheave arrangement 22 is rotated so that the (flat,belt-type) suspension media 4 is sufficiently parallel to an imaginaryline connecting the cabin and counterweight centerlines. The optimalinterface angle is a combination of the angle the through holes in thehitch plate 32 makes with the yoke, and the angle each individual sheave22 a is set at so that smallest amount of twist is imparted to the flatsuspension media 4. The determined interface angle may not be the finalangle; it is contemplated that the hitch plate 32 can be rotated andfine tuned at any time during the installation procedure.

In a step S3, components of the coupling system 12 are pre-set. A sidewall 30 is placed on each side of the yoke, and nuts and washers areattached on each side of each rod 34 to set an absolute minimum width ofthe distance between the side walls 30. These sides of the rods 34 havein one embodiment threaded portions. When installed, these nuts andwashers are placed on inner sides of the side walls 30, as shown, e.g.,in FIG. 3. The side walls 30 should be positioned symmetrically to thecenter of the hitch plate 32. The nuts and washers placed on the rods 34are adjusted on the rods 34 as needed to achieve that positioning.

In a step S4, the components of the coupling system 12 arepre-assembled. The side walls 30 are initially loosely fitted around theyoke with the hitch plate 32 inserted into the openings 38 of the sidewalls 30. One way of achieving that initial fitment is to insert thehitch plate 32 into the opening 38 of one side wall 30, insert the rods34 into their respective holes of that side walls 30, and to place thesecond side wall 30 onto the rods 34 with the hitch plate 32 insertedinto the opening 38 of that side wall 30.

In a step S5, the crossbars 36 are inserted into the opening 46 of eachside wall 30. The crossbars 36 may be secured within the opening 46 ofone side wall 30.

In a step S6, the setscrews 48, 48 a are mounted to the hitch plate 32.The setscrews 48, 48 a are adjusted to rest on the surface of the yoke.The height of the hitch plate 32 is adjusted to ensure proper fitmentbeneath the yoke for the crossbars 36. The setscrews 48, 48 a are thenadjusted for proper fitment of the hitch plate 32 above the yoke.

As mentioned above, each side wall 30 may be formed by four individualplates. In such an embodiment, these plates can now mounted to the rods34 on each side of the yoke.

In a step S7, once proper fitment has been verified, the assembly isverified and all screw connections are tightened. It is then againverified that a tight fitment has been made without any risk of play,that the hitch plate 32 is centered and secured in the openings 38 ofthe side walls 30. In one embodiment, the hitch plate 32 sticks out atleast about 31.75 mm further than an outer side of the side walls 30.

In a step S8, the tie bolts 22 c together with the sheaves 22 a aremounted to the hitch plate 32 and secured on the underside of the hitchplate 32 through nuts and split pins. Once mounted, the tie bolts 22 cextend through the hitch plate 32 towards the sheave arrangement 22, asshown in FIG. 2.

In a step S9, a suspension medium 4 is inserted (roped) into each sheave22 a. The sheaves 22 are adjusted and fastened, as needed. This step isrepeated until all suspension media 4 are inserted into the sheaves 22a.

In a step S10, the setscrews 40, 40 a are inserted into the slots 42.The setscrews 40, 40 a are adjusted to press against the yoke forhorizontal positioning of the coupling system 12 with respect to theyoke.

The various components of the coupling system 12 described withreference to FIGS. 2-7 make the coupling system 12 to modular design.The modular design of the coupling system 12 significantly eases theinstallation process. Each individual component is relativelylightweight and can be handled separately. In one embodiment, each sidewall 30 may be formed by individual wall panels. As shown, e.g., inFIGS. 3 and 4, each side wall 30 is formed by four thin and, hence,lightweight wall panels. It is contemplated that the number ofindividual wall panels may vary depending on certain load requirements.

Furthermore, individual components of the coupling system 12 may bereplaced separately, if needed. These components may be selecteddepending on particular or changing load requirements.

It is apparent that there has been disclosed a system and method forcoupling a suspension medium to a load carrying structure of an elevatorinstallation that fully satisfy the objects, means, and advantages setforth herein before. For example, the coupling system 12 serves as aninterface between the suspension media 4 and the cabin 2 and is inparticular advantageous for modernizing elevator installations where theexisting cabin and counterweight is to be retained without anymodification. The coupling system 12 with its rotatable hitch plate 32is designed to accommodate any installation angle on both the cabin andthe counterweight side which is due to varying hoistway layouts. Inaddition, the coupling system 12, due to its rectangular opening (seee.g. FIG. 4) accommodates to a variety of yoke profiles. The interfaceformed by the coupling system 12 does not require any drilling on-site(e.g. through the yoke) and does not require yoke or cross headmodifications.

What is claimed is:
 1. A system for coupling a suspension medium to aload carrying structure of an elevator installation, comprising: a framehaving two spaced apart side walls extending in parallel planes, theside walls being interconnected by at least one rod extending throughboth of the side walls, wherein the side walls are positionable alongthe at least one rod to receive a part of the load carrying structurebetween the side walls, and wherein each of the side walls has areceptacle having a predetermined shape; and a hitch plate having aleast one fixture configured to couple to a pulley arrangement for thesuspension medium, wherein each receptacle is sized to rotatably receivea section of the hitch plate so that the hitch plate extends between theside walls and is rotatable about a vertical axis.
 2. The system ofclaim 1, wherein the hitch plate has a circular shape.
 3. The system ofclaim 2, wherein sections of the circularly shaped hitch plate extendthrough the receptacles.
 4. The system of claim 2, wherein the hitchplate is configured to be rotatable between about 0° and about 360° . 5.The system of claim 1, wherein the at least one fixture includes anopening sized to receive a rod of the pulley arrangement.
 6. The systemof claim 5, wherein a plurality of the openings is positioned along twostraight perpendicular lines:
 7. The system of claim 1, furthercomprising a predetermined number of rods, including the at least onerod, extending between the side walls and interconnecting the sidewalls.
 8. The system of claim 7, wherein each side wall has acorresponding number of passageways, each removably receiving an endsection of an associated one of the rods.
 9. The system of claim 1,wherein each side wall has an upper part containing the receptacle, anda bottom part having an opening for a crossbeam.
 10. The system of claim1, further comprising first setscrews extending through the hitch plateand configured to press against an upper surface of the supportstructure for vertical positioning of the system with respect to theload carrying structure, and second setscrews extending through the sidewalls to press against sides of the support structure for horizontalpositioning of the system.
 11. The system of claim 10, wherein eachsetscrew has a bearing surface pressing against the load carryingstructure that includes a material selected to dampen vibrations. 12.The system of claim 1, wherein an axis of the hitch plate issubstantially parallel with the side walls.
 13. An elevatorinstallation, comprising: a suspension medium; a sheave arrangement,coupled to the suspension medium; a load carrying structure; and acoupling system configured to couple the sheave arrangement to the loadcarrying structure, wherein the coupling system comprises: a framehaving two spaced apart side walls extending in parallel planes, theside walls being interconnected by at least one rod extending throughboth of the side walls, wherein the side walls are positionable alongthe at least one rod to receive a part of the load carrying structurebetween the side walls, and wherein each of the side walls has areceptacle having a predetermined shape; and a hitch plate having aleast one fixture configured to couple to the sheave arrangement,wherein each receptacle is sized to rotatably receive a section of thehitch plate so that the hitch plate extends between the side walls andis rotatable about a vertical axis.
 14. The installation of claim 13,wherein the hitch plate has a circular shape.
 15. The installation ofclaim 14, wherein sections of the circularly shaped hitch plate extendthrough the receptacles.
 16. The installation of claim 14, wherein thehitch plate is configured to be rotatable between about 0° and about360° .
 17. The installation of claim 13, wherein an axis of the hitchplate is substantially parallel with the side walls.
 18. A method ofcoupling a suspension medium to a load carrying structure of an elevatorinstallation, comprising: positioning a hitch plate above a part of aload carrying structure; mounting two side walls to the hitch plate sothat sections of the hitch plate are rotatably positioned in receptaclesof the side walls and the part of the load carrying structure extendsbetween the side walls, wherein the side walls are opposite each otherand extend in parallel planes, the side walls being interconnected by atleast one rod extending through both of the side walls to form a frameand the side walls being positionable along the at least one rod; andmounting a sheave arrangement to the hitch plate, wherein the sheavearrangement is configured to receive the suspension medium.
 19. Themethod of claim 18, wherein mounting the side walls includes connectingthe side walls by means of rods, including the at least one rod, andinserting a crossbeam into an opening at the bottom and on each sidewall, wherein the crossbeam extends underneath the part of the loadcarrying structure.
 20. The method of claim 18, further comprisingmounting setscrews to the hitch plate to fix a vertical position of thehitch plate with respect to the part of the load carrying structure, andmounting setscrews to the side walls to fix a horizontal position of thepart of the load carrying structure with respect to the sidewalls.